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  <div class="section" id="module-asyncore">
<span id="asyncore-asynchronous-socket-handler"></span><h1><a class="reference internal" href="#module-asyncore" title="asyncore: A base class for developing asynchronous socket handling services."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncore</span></code></a> --- 异步socket处理器<a class="headerlink" href="#module-asyncore" title="永久链接至标题">¶</a></h1>
<p><strong>源码：</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.7/Lib/asyncore.py">Lib/asyncore.py</a></p>
<div class="deprecated">
<p><span class="versionmodified deprecated">3.6 版后已移除: </span>请使用 <a class="reference internal" href="asyncio.html#module-asyncio" title="asyncio: Asynchronous I/O."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncio</span></code></a> 替代。</p>
</div>
<hr class="docutils" />
<div class="admonition note">
<p class="admonition-title">注解</p>
<p>该模块仅为提供向后兼容。我们推荐在新代码中使用 <a class="reference internal" href="asyncio.html#module-asyncio" title="asyncio: Asynchronous I/O."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncio</span></code></a> 。</p>
</div>
<p>该模块提供用于编写异步套接字服务客户端与服务端的基础构件。</p>
<p>只有两种方法让单个处理器上的程序“同一时间完成不止一件事”。 多线程编程是最简单和最流行的方法，但是还有另一种非常不同的技术，它可以让你拥有多线程的几乎所有优点，而无需实际使用多线程。 它仅仅在你的程序主要受 I/O 限制时有用，那么。 如果你的程序受处理器限制，那么先发制人的预定线程可能就是你真正需要的。 但是，网络服务器很少受处理器限制。</p>
<p>如果你的操作系统在其 I/O 库中支持 <code class="xref c c-func docutils literal notranslate"><span class="pre">select()</span></code> 系统调用（几乎所有操作系统），那么你可以使用它来同时处理多个通信通道；在 I/O 正在“后台”时进行其他工作。 虽然这种策略看起来很奇怪和复杂，特别是起初，它在很多方面比多线程编程更容易理解和控制。 <a class="reference internal" href="#module-asyncore" title="asyncore: A base class for developing asynchronous socket handling services."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncore</span></code></a> 模块为您解决了许多难题，使得构建复杂的高性能网络服务器和客户端的任务变得轻而易举。 对于“会话”应用程序和协议，伴侣 <a class="reference internal" href="asynchat.html#module-asynchat" title="asynchat: Support for asynchronous command/response protocols."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asynchat</span></code></a> 模块是非常宝贵的。</p>
<p>这两个模块背后的基本思想是创建一个或多个网络 <em>通道</em> ，类的实例 <a class="reference internal" href="#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a> 和 <a class="reference internal" href="asynchat.html#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">asynchat.async_chat</span></code></a> 。 创建通道会将它们添加到全局映射中，如果你不为它提供自己的 <em>映射</em> ，则由 <a class="reference internal" href="#asyncore.loop" title="asyncore.loop"><code class="xref py py-func docutils literal notranslate"><span class="pre">loop()</span></code></a> 函数使用。</p>
<p>一旦创建了初始通道，调用 <a class="reference internal" href="#asyncore.loop" title="asyncore.loop"><code class="xref py py-func docutils literal notranslate"><span class="pre">loop()</span></code></a> 函数将激活通道服务，该服务将一直持续到最后一个通道（包括在异步服务期间已添加到映射中的任何通道）关闭。</p>
<dl class="function">
<dt id="asyncore.loop">
<code class="sig-prename descclassname">asyncore.</code><code class="sig-name descname">loop</code><span class="sig-paren">(</span><span class="optional">[</span><em class="sig-param">timeout</em><span class="optional">[</span>, <em class="sig-param">use_poll</em><span class="optional">[</span>, <em class="sig-param">map</em><span class="optional">[</span>, <em class="sig-param">count</em><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.loop" title="永久链接至目标">¶</a></dt>
<dd><p>进入一个轮询循环，其在循环计数超出或所有打开的通道关闭后终止。 所有参数都是可选的。 <em>count</em> 形参默认为 <code class="docutils literal notranslate"><span class="pre">None</span></code> ，导致循环仅在所有通道关闭时终止。 <em>timeout</em> 形参为适当的 <a class="reference internal" href="select.html#select.select" title="select.select"><code class="xref py py-func docutils literal notranslate"><span class="pre">select()</span></code></a> 或 <a class="reference internal" href="select.html#select.poll" title="select.poll"><code class="xref py py-func docutils literal notranslate"><span class="pre">poll()</span></code></a> 调用设置超时参数，以秒为单位; 默认值为30秒。 <em>use_poll</em> 形参，如果为 True ，则表示 <a class="reference internal" href="select.html#select.poll" title="select.poll"><code class="xref py py-func docutils literal notranslate"><span class="pre">poll()</span></code></a> 应优先使用 <code class="xref py py-func docutils literal notranslate"><span class="pre">select`（默认为``False`()</span></code>）。</p>
<p>The <em>map</em> parameter is a dictionary whose items are the channels to watch.
As channels are closed they are deleted from their map.  If <em>map</em> is
omitted, a global map is used. Channels (instances of
<a class="reference internal" href="#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncore.dispatcher</span></code></a>, <a class="reference internal" href="asynchat.html#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">asynchat.async_chat</span></code></a> and subclasses
thereof) can freely be mixed in the map.</p>
</dd></dl>

<dl class="class">
<dt id="asyncore.dispatcher">
<em class="property">class </em><code class="sig-prename descclassname">asyncore.</code><code class="sig-name descname">dispatcher</code><a class="headerlink" href="#asyncore.dispatcher" title="永久链接至目标">¶</a></dt>
<dd><p>The <a class="reference internal" href="#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">dispatcher</span></code></a> class is a thin wrapper around a low-level socket
object. To make it more useful, it has a few methods for event-handling
which are called from the asynchronous loop.   Otherwise, it can be treated
as a normal non-blocking socket object.</p>
<p>The firing of low-level events at certain times or in certain connection
states tells the asynchronous loop that certain higher-level events have
taken place.  For example, if we have asked for a socket to connect to
another host, we know that the connection has been made when the socket
becomes writable for the first time (at this point you know that you may
write to it with the expectation of success).  The implied higher-level
events are:</p>
<table class="docutils align-default">
<colgroup>
<col style="width: 35%" />
<col style="width: 65%" />
</colgroup>
<thead>
<tr class="row-odd"><th class="head"><p>Event</p></th>
<th class="head"><p>描述</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">handle_connect()</span></code></p></td>
<td><p>Implied by the first read or write
event</p></td>
</tr>
<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">handle_close()</span></code></p></td>
<td><p>Implied by a read event with no data
available</p></td>
</tr>
<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">handle_accepted()</span></code></p></td>
<td><p>Implied by a read event on a listening
socket</p></td>
</tr>
</tbody>
</table>
<p>During asynchronous processing, each mapped channel's <a class="reference internal" href="#asyncore.dispatcher.readable" title="asyncore.dispatcher.readable"><code class="xref py py-meth docutils literal notranslate"><span class="pre">readable()</span></code></a> and
<a class="reference internal" href="#asyncore.dispatcher.writable" title="asyncore.dispatcher.writable"><code class="xref py py-meth docutils literal notranslate"><span class="pre">writable()</span></code></a> methods are used to determine whether the channel's socket
should be added to the list of channels <code class="xref c c-func docutils literal notranslate"><span class="pre">select()</span></code>ed or
<code class="xref c c-func docutils literal notranslate"><span class="pre">poll()</span></code>ed for read and write events.</p>
<p>Thus, the set of channel events is larger than the basic socket events.  The
full set of methods that can be overridden in your subclass follows:</p>
<dl class="method">
<dt id="asyncore.dispatcher.handle_read">
<code class="sig-name descname">handle_read</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_read" title="永久链接至目标">¶</a></dt>
<dd><p>Called when the asynchronous loop detects that a <code class="xref py py-meth docutils literal notranslate"><span class="pre">read()</span></code> call on the
channel's socket will succeed.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.handle_write">
<code class="sig-name descname">handle_write</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_write" title="永久链接至目标">¶</a></dt>
<dd><p>Called when the asynchronous loop detects that a writable socket can be
written.  Often this method will implement the necessary buffering for
performance.  For example:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">handle_write</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
    <span class="n">sent</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">send</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">buffer</span><span class="p">)</span>
    <span class="bp">self</span><span class="o">.</span><span class="n">buffer</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">buffer</span><span class="p">[</span><span class="n">sent</span><span class="p">:]</span>
</pre></div>
</div>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.handle_expt">
<code class="sig-name descname">handle_expt</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_expt" title="永久链接至目标">¶</a></dt>
<dd><p>Called when there is out of band (OOB) data for a socket connection.  This
will almost never happen, as OOB is tenuously supported and rarely used.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.handle_connect">
<code class="sig-name descname">handle_connect</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_connect" title="永久链接至目标">¶</a></dt>
<dd><p>Called when the active opener's socket actually makes a connection.  Might
send a &quot;welcome&quot; banner, or initiate a protocol negotiation with the
remote endpoint, for example.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.handle_close">
<code class="sig-name descname">handle_close</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_close" title="永久链接至目标">¶</a></dt>
<dd><p>Called when the socket is closed.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.handle_error">
<code class="sig-name descname">handle_error</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_error" title="永久链接至目标">¶</a></dt>
<dd><p>Called when an exception is raised and not otherwise handled.  The default
version prints a condensed traceback.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.handle_accept">
<code class="sig-name descname">handle_accept</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_accept" title="永久链接至目标">¶</a></dt>
<dd><p>Called on listening channels (passive openers) when a connection can be
established with a new remote endpoint that has issued a <a class="reference internal" href="#asyncore.dispatcher.connect" title="asyncore.dispatcher.connect"><code class="xref py py-meth docutils literal notranslate"><span class="pre">connect()</span></code></a>
call for the local endpoint. Deprecated in version 3.2; use
<a class="reference internal" href="#asyncore.dispatcher.handle_accepted" title="asyncore.dispatcher.handle_accepted"><code class="xref py py-meth docutils literal notranslate"><span class="pre">handle_accepted()</span></code></a> instead.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">3.2 版后已移除.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.handle_accepted">
<code class="sig-name descname">handle_accepted</code><span class="sig-paren">(</span><em class="sig-param">sock</em>, <em class="sig-param">addr</em><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.handle_accepted" title="永久链接至目标">¶</a></dt>
<dd><p>Called on listening channels (passive openers) when a connection has been
established with a new remote endpoint that has issued a <a class="reference internal" href="#asyncore.dispatcher.connect" title="asyncore.dispatcher.connect"><code class="xref py py-meth docutils literal notranslate"><span class="pre">connect()</span></code></a>
call for the local endpoint.  <em>sock</em> is a <em>new</em> socket object usable to
send and receive data on the connection, and <em>addr</em> is the address
bound to the socket on the other end of the connection.</p>
<div class="versionadded">
<p><span class="versionmodified added">3.2 新版功能.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.readable">
<code class="sig-name descname">readable</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.readable" title="永久链接至目标">¶</a></dt>
<dd><p>Called each time around the asynchronous loop to determine whether a
channel's socket should be added to the list on which read events can
occur.  The default method simply returns <code class="docutils literal notranslate"><span class="pre">True</span></code>, indicating that by
default, all channels will be interested in read events.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.writable">
<code class="sig-name descname">writable</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.writable" title="永久链接至目标">¶</a></dt>
<dd><p>Called each time around the asynchronous loop to determine whether a
channel's socket should be added to the list on which write events can
occur.  The default method simply returns <code class="docutils literal notranslate"><span class="pre">True</span></code>, indicating that by
default, all channels will be interested in write events.</p>
</dd></dl>

<p>In addition, each channel delegates or extends many of the socket methods.
Most of these are nearly identical to their socket partners.</p>
<dl class="method">
<dt id="asyncore.dispatcher.create_socket">
<code class="sig-name descname">create_socket</code><span class="sig-paren">(</span><em class="sig-param">family=socket.AF_INET</em>, <em class="sig-param">type=socket.SOCK_STREAM</em><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.create_socket" title="永久链接至目标">¶</a></dt>
<dd><p>This is identical to the creation of a normal socket, and will use the
same options for creation.  Refer to the <a class="reference internal" href="socket.html#module-socket" title="socket: Low-level networking interface."><code class="xref py py-mod docutils literal notranslate"><span class="pre">socket</span></code></a> documentation for
information on creating sockets.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">在 3.3 版更改: </span><em>family</em> and <em>type</em> arguments can be omitted.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.connect">
<code class="sig-name descname">connect</code><span class="sig-paren">(</span><em class="sig-param">address</em><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.connect" title="永久链接至目标">¶</a></dt>
<dd><p>As with the normal socket object, <em>address</em> is a tuple with the first
element the host to connect to, and the second the port number.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.send">
<code class="sig-name descname">send</code><span class="sig-paren">(</span><em class="sig-param">data</em><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.send" title="永久链接至目标">¶</a></dt>
<dd><p>Send <em>data</em> to the remote end-point of the socket.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.recv">
<code class="sig-name descname">recv</code><span class="sig-paren">(</span><em class="sig-param">buffer_size</em><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.recv" title="永久链接至目标">¶</a></dt>
<dd><p>Read at most <em>buffer_size</em> bytes from the socket's remote end-point.  An
empty bytes object implies that the channel has been closed from the
other end.</p>
<p>Note that <a class="reference internal" href="#asyncore.dispatcher.recv" title="asyncore.dispatcher.recv"><code class="xref py py-meth docutils literal notranslate"><span class="pre">recv()</span></code></a> may raise <a class="reference internal" href="exceptions.html#BlockingIOError" title="BlockingIOError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">BlockingIOError</span></code></a> , even though
<a class="reference internal" href="select.html#select.select" title="select.select"><code class="xref py py-func docutils literal notranslate"><span class="pre">select.select()</span></code></a> or <a class="reference internal" href="select.html#select.poll" title="select.poll"><code class="xref py py-func docutils literal notranslate"><span class="pre">select.poll()</span></code></a> has reported the socket
ready for reading.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.listen">
<code class="sig-name descname">listen</code><span class="sig-paren">(</span><em class="sig-param">backlog</em><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.listen" title="永久链接至目标">¶</a></dt>
<dd><p>Listen for connections made to the socket.  The <em>backlog</em> argument
specifies the maximum number of queued connections and should be at least
1; the maximum value is system-dependent (usually 5).</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.bind">
<code class="sig-name descname">bind</code><span class="sig-paren">(</span><em class="sig-param">address</em><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.bind" title="永久链接至目标">¶</a></dt>
<dd><p>Bind the socket to <em>address</em>.  The socket must not already be bound.  (The
format of <em>address</em> depends on the address family --- refer to the
<a class="reference internal" href="socket.html#module-socket" title="socket: Low-level networking interface."><code class="xref py py-mod docutils literal notranslate"><span class="pre">socket</span></code></a> documentation for more information.)  To mark
the socket as re-usable (setting the <code class="xref py py-const docutils literal notranslate"><span class="pre">SO_REUSEADDR</span></code> option), call
the <a class="reference internal" href="#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">dispatcher</span></code></a> object's <code class="xref py py-meth docutils literal notranslate"><span class="pre">set_reuse_addr()</span></code> method.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.accept">
<code class="sig-name descname">accept</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.accept" title="永久链接至目标">¶</a></dt>
<dd><p>Accept a connection.  The socket must be bound to an address and listening
for connections.  The return value can be either <code class="docutils literal notranslate"><span class="pre">None</span></code> or a pair
<code class="docutils literal notranslate"><span class="pre">(conn,</span> <span class="pre">address)</span></code> where <em>conn</em> is a <em>new</em> socket object usable to send
and receive data on the connection, and <em>address</em> is the address bound to
the socket on the other end of the connection.
When <code class="docutils literal notranslate"><span class="pre">None</span></code> is returned it means the connection didn't take place, in
which case the server should just ignore this event and keep listening
for further incoming connections.</p>
</dd></dl>

<dl class="method">
<dt id="asyncore.dispatcher.close">
<code class="sig-name descname">close</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#asyncore.dispatcher.close" title="永久链接至目标">¶</a></dt>
<dd><p>Close the socket.  All future operations on the socket object will fail.
The remote end-point will receive no more data (after queued data is
flushed).  Sockets are automatically closed when they are
garbage-collected.</p>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="asyncore.dispatcher_with_send">
<em class="property">class </em><code class="sig-prename descclassname">asyncore.</code><code class="sig-name descname">dispatcher_with_send</code><a class="headerlink" href="#asyncore.dispatcher_with_send" title="永久链接至目标">¶</a></dt>
<dd><p>A <a class="reference internal" href="#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">dispatcher</span></code></a> subclass which adds simple buffered output capability,
useful for simple clients. For more sophisticated usage use
<a class="reference internal" href="asynchat.html#asynchat.async_chat" title="asynchat.async_chat"><code class="xref py py-class docutils literal notranslate"><span class="pre">asynchat.async_chat</span></code></a>.</p>
</dd></dl>

<dl class="class">
<dt id="asyncore.file_dispatcher">
<em class="property">class </em><code class="sig-prename descclassname">asyncore.</code><code class="sig-name descname">file_dispatcher</code><a class="headerlink" href="#asyncore.file_dispatcher" title="永久链接至目标">¶</a></dt>
<dd><p>A file_dispatcher takes a file descriptor or <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file object</span></a> along
with an optional map argument and wraps it for use with the <code class="xref c c-func docutils literal notranslate"><span class="pre">poll()</span></code>
or <code class="xref c c-func docutils literal notranslate"><span class="pre">loop()</span></code> functions.  If provided a file object or anything with a
<code class="xref c c-func docutils literal notranslate"><span class="pre">fileno()</span></code> method, that method will be called and passed to the
<a class="reference internal" href="#asyncore.file_wrapper" title="asyncore.file_wrapper"><code class="xref py py-class docutils literal notranslate"><span class="pre">file_wrapper</span></code></a> constructor.</p>
<p class="availability"><a class="reference internal" href="intro.html#availability"><span class="std std-ref">可用性</span></a>: Unix。</p>
</dd></dl>

<dl class="class">
<dt id="asyncore.file_wrapper">
<em class="property">class </em><code class="sig-prename descclassname">asyncore.</code><code class="sig-name descname">file_wrapper</code><a class="headerlink" href="#asyncore.file_wrapper" title="永久链接至目标">¶</a></dt>
<dd><p>A file_wrapper takes an integer file descriptor and calls <a class="reference internal" href="os.html#os.dup" title="os.dup"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.dup()</span></code></a> to
duplicate the handle so that the original handle may be closed independently
of the file_wrapper.  This class implements sufficient methods to emulate a
socket for use by the <a class="reference internal" href="#asyncore.file_dispatcher" title="asyncore.file_dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">file_dispatcher</span></code></a> class.</p>
<p class="availability"><a class="reference internal" href="intro.html#availability"><span class="std std-ref">可用性</span></a>: Unix。</p>
</dd></dl>

<div class="section" id="asyncore-example-basic-http-client">
<span id="asyncore-example-1"></span><h2>asyncore Example basic HTTP client<a class="headerlink" href="#asyncore-example-basic-http-client" title="永久链接至标题">¶</a></h2>
<p>Here is a very basic HTTP client that uses the <a class="reference internal" href="#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">dispatcher</span></code></a> class to
implement its socket handling:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">asyncore</span>

<span class="k">class</span> <span class="nc">HTTPClient</span><span class="p">(</span><span class="n">asyncore</span><span class="o">.</span><span class="n">dispatcher</span><span class="p">):</span>

    <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">host</span><span class="p">,</span> <span class="n">path</span><span class="p">):</span>
        <span class="n">asyncore</span><span class="o">.</span><span class="n">dispatcher</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">create_socket</span><span class="p">()</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">connect</span><span class="p">(</span> <span class="p">(</span><span class="n">host</span><span class="p">,</span> <span class="mi">80</span><span class="p">)</span> <span class="p">)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">buffer</span> <span class="o">=</span> <span class="nb">bytes</span><span class="p">(</span><span class="s1">&#39;GET </span><span class="si">%s</span><span class="s1"> HTTP/1.0</span><span class="se">\r\n</span><span class="s1">Host: </span><span class="si">%s</span><span class="se">\r\n\r\n</span><span class="s1">&#39;</span> <span class="o">%</span>
                            <span class="p">(</span><span class="n">path</span><span class="p">,</span> <span class="n">host</span><span class="p">),</span> <span class="s1">&#39;ascii&#39;</span><span class="p">)</span>

    <span class="k">def</span> <span class="nf">handle_connect</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">pass</span>

    <span class="k">def</span> <span class="nf">handle_close</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>

    <span class="k">def</span> <span class="nf">handle_read</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="nb">print</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">recv</span><span class="p">(</span><span class="mi">8192</span><span class="p">))</span>

    <span class="k">def</span> <span class="nf">writable</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">return</span> <span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">buffer</span><span class="p">)</span> <span class="o">&gt;</span> <span class="mi">0</span><span class="p">)</span>

    <span class="k">def</span> <span class="nf">handle_write</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="n">sent</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">send</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">buffer</span><span class="p">)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">buffer</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">buffer</span><span class="p">[</span><span class="n">sent</span><span class="p">:]</span>


<span class="n">client</span> <span class="o">=</span> <span class="n">HTTPClient</span><span class="p">(</span><span class="s1">&#39;www.python.org&#39;</span><span class="p">,</span> <span class="s1">&#39;/&#39;</span><span class="p">)</span>
<span class="n">asyncore</span><span class="o">.</span><span class="n">loop</span><span class="p">()</span>
</pre></div>
</div>
</div>
<div class="section" id="asyncore-example-basic-echo-server">
<span id="asyncore-example-2"></span><h2>asyncore Example basic echo server<a class="headerlink" href="#asyncore-example-basic-echo-server" title="永久链接至标题">¶</a></h2>
<p>Here is a basic echo server that uses the <a class="reference internal" href="#asyncore.dispatcher" title="asyncore.dispatcher"><code class="xref py py-class docutils literal notranslate"><span class="pre">dispatcher</span></code></a> class to accept
connections and dispatches the incoming connections to a handler:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">asyncore</span>

<span class="k">class</span> <span class="nc">EchoHandler</span><span class="p">(</span><span class="n">asyncore</span><span class="o">.</span><span class="n">dispatcher_with_send</span><span class="p">):</span>

    <span class="k">def</span> <span class="nf">handle_read</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="n">data</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">recv</span><span class="p">(</span><span class="mi">8192</span><span class="p">)</span>
        <span class="k">if</span> <span class="n">data</span><span class="p">:</span>
            <span class="bp">self</span><span class="o">.</span><span class="n">send</span><span class="p">(</span><span class="n">data</span><span class="p">)</span>

<span class="k">class</span> <span class="nc">EchoServer</span><span class="p">(</span><span class="n">asyncore</span><span class="o">.</span><span class="n">dispatcher</span><span class="p">):</span>

    <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">):</span>
        <span class="n">asyncore</span><span class="o">.</span><span class="n">dispatcher</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">create_socket</span><span class="p">()</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">set_reuse_addr</span><span class="p">()</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">bind</span><span class="p">((</span><span class="n">host</span><span class="p">,</span> <span class="n">port</span><span class="p">))</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">listen</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>

    <span class="k">def</span> <span class="nf">handle_accepted</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">sock</span><span class="p">,</span> <span class="n">addr</span><span class="p">):</span>
        <span class="nb">print</span><span class="p">(</span><span class="s1">&#39;Incoming connection from </span><span class="si">%s</span><span class="s1">&#39;</span> <span class="o">%</span> <span class="nb">repr</span><span class="p">(</span><span class="n">addr</span><span class="p">))</span>
        <span class="n">handler</span> <span class="o">=</span> <span class="n">EchoHandler</span><span class="p">(</span><span class="n">sock</span><span class="p">)</span>

<span class="n">server</span> <span class="o">=</span> <span class="n">EchoServer</span><span class="p">(</span><span class="s1">&#39;localhost&#39;</span><span class="p">,</span> <span class="mi">8080</span><span class="p">)</span>
<span class="n">asyncore</span><span class="o">.</span><span class="n">loop</span><span class="p">()</span>
</pre></div>
</div>
</div>
</div>


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<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncore</span></code> --- 异步socket处理器</a><ul>
<li><a class="reference internal" href="#asyncore-example-basic-http-client">asyncore Example basic HTTP client</a></li>
<li><a class="reference internal" href="#asyncore-example-basic-echo-server">asyncore Example basic echo server</a></li>
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